So California especially, they balance solar with natural gas. In Germany, they balance wind with coal. And this leads to this very ironic situation where the places with the highest penetration of renewables also have greenhouse gas emissions which are going up.

DAVIES: And this is a fascinating thing that you describe where a utility will literally have an old plant running on fossil fuels – coal or diesel – and it sits idle until there’s a decline in some other energy source. And then they fire up this expensive, antiquated, polluting equipment?

BAKKE: Exactly. Yeah, either a dip in another energy source or a big surge in use. So we usually use – they’re called peakers, and we usually use them, for example, on a very hot August day when everyone turns up their air conditioning. So that’s another case where the plants that are making electricity aren’t making enough. And so these plants have to get turned on.

But you need all the coal sitting around to run them. You need the people sitting around to be called in to run them because they’re complicated machines – giant complicated machines.

DAVIES: So if we – if the people, if the utilities, if the grid could figure out a way to manage all this renewable energy coming in and not have to have these old, antiquated plants at the ready, it would save a lot of money, effort and pollution, right?

BAKKE: Absolutely. Absolutely. And one of the things, for example, that Texas is doing right now, they have the highest amount of wind energy in the country. And they – their – Texas wind blows at night, so they’ve done two funny things. One is that there’s one utility that just gives away electricity after 9 p.m.

So the electricity is free, again, because they need people to use it. So everybody at 9:00 p.m., everybody sort of stands up and turns on their dishwasher

.. I think that this idea – the idea that with either zero or we’ve failed needs to be put aside a little bit to say, what would it look like if we could get to 80 percent? How would we have to revive – what would we have to do to the system in order to get to 80 percent renewables – because once we can do that, then we can look at and say, how do we get to 90 percent – as opposed to this sort of we’re going to completely eliminate any kind of fossil fuel, leave it all on the ground, and we’re going to run all on renewables.

The upside of renewables is that they can for sure make more electricity than we need. There’s not – there’s not a shortage problem. There’s, in a way, an excess problem. But that is not – that’s not the issue. That’s in part why I feel like this book actually matters is because it’s not about generation. That’s not the end of the story. That’s the beginning of the story. And the rest of the story is about the ways in which we use that power, the ways in which we transmit that power, the ways in which we care for that power, we store that power or we don’t store it, we balance it – all of these grid-related sort of human questions.

So, yes, absolutely, I think it’s absolutely possible. But let’s get to 50 percent. Let’s get to – I think 80 percent – by the time we get to 80 percent renewable and integration, we are going to have confronted all of the big problems that are facing us right now.